The opinion of the court was delivered by: Oliver W. Wanger United States District Judge
CONCLUSIONS OF LAW RE: FINDINGS OF FACT AND MOTION TO EXCLUDE TESTIMONY OF CAMILLE SEARS AND NEED FOR FED.R.EVID. 706 EXPERTS
Following the hearing on Defendants Merck & Co., Inc.'s, Amsted Industries, Inc.'s, Baltimore Aircoil Company, Inc.'s, and TrackFour, Inc.'s (collectively, the "BAC Defendants") Daubert motions, the following Findings of Fact and Conclusions of Law are entered.
1. On June 1, 2010, the BAC Defendants moved pursuant to Federal Rules of Evidence 702 and 703 to exclude the testimony of Plaintiffs' expert witness Camille Sears. The parties submitted voluminous declarations and exhibits, and the Court held approximately four days of hearings on Defendants' motion and related motions to exclude evidence and for partial summary judgment.
2. Ms. Sears is an atmospheric scientist and meteorologist. Ms. Sears acknowledges that she does not consider herself an expert in the fields of chemistry, hydrogeology, geochemistry, wood treating/wood science, or soil science. (See 10/13/10 Hearing Transcript (rough) at 85:15-23; 86:10-12, 16-24; 87:3-18; 88:1-89:4).
3. The relevant science and field of expertise is air emissions and air modeling. Chemistry and geochemistry also apply.
4. Ms. Sears prepared a mathematical model that Plaintiffs have offered as evidence that hexavalent chromium and arsenic were transported in air from the former Baltimore Aircoil Company facility located in Merced County, California ("the BAC Site") to Plaintiffs' residences. Ms. Sears modeled the period from 1969 through 1993 to support her opinion that residents of the BAC Site were exposed to elevated air concentrations of hexavalent chromium and arsenic during that period.
5. Plaintiffs have not adduced a date or a model suggesting that any area of Plaintiffs' residences was exposed by air transmission of those contaminants during the period 1994 to the present.
6. Ms. Sears' model purports to estimate air emissions of hexavalent chromium and arsenic from dust stirred up by forklifts driving on the treated wood storage area on the Site during the period 1969-1991. Wood treatment was conducted in a cylindrical pressure vessel ("retort") at the BAC Site. From 1969 to 1980, a chromium- and arsenic-containing solution known as chromated copper arsenate or "CCA" was applied to the wood under pressure in the retort. From 1980 to 1991, an acid copper chromate or "ACC" solution was used that did not contain arsenic. After the wood was removed from the retort, it was left to dry on a drip pad and then was transferred to the treated wood storage area. The retort and adjacent drip pad area were paved with asphalt and concrete; the treated wood storage area was approximately 95 percent paved and 5 percent unimproved natural ground surface.
7. Ms. Sears assumed that wood-treating solution dripped onto the treated wood storage area, dried to form "silt," and was later disturbed by forklifts that drove on the site.
8. Ms. Sears used an emission algorithm published by the U.S. Environmental Protection Agency ("EPA") known as AP-42, Section 13.2.1, to model how much dust would be emitted into the air by forklifts operating at the BAC Site. The inputs to the AP-42 algorithm include (i) a particulate emission factor; (ii) a particle size multiplier for the particle size range and units of interest; (iii) a road surface silt loading factor in grams per square meter; (iv) the average weight in tons of the vehicles traveling the road; and (v) an emission factor for 1980s vehicle fleet exhaust, brake wear and tire wear.
9. The AP-42 algorithm was based on tests of "freely flowing traffic" with vehicle speeds between 10 and 60 miles per hour on paved highways.
10. Ms. Sears' application of AP-42 to the BAC Site has been challenged because, as she testified, vehicles traveling at constant speeds in excess of 10 miles per hour were not present in the retort or wood storage areas of the former BAC Site; rather, the Site was traversed by forklifts traveling at less than 10 miles per hour that stopped and started frequently.
11. Ms. Sears has not cited any authority that applies AP-42, Section 13.2.1, to model stop-and-go operations of forklifts traveling at average ...